This invention relates to a method and apparatus for characterizing biological activity. More particularly, this invention relates to a rapid and economical method and apparatus for identifying microorganisms, viruses, enzymes, etc. through an analysis of their activity toward fermentation of common biodegradable substances. The term "fermentable" is intended to mean capable of being broken down into simpler compounds by the action of a biologically active agent. The invention is especially suitable for identifying medically significant bacteria by monitoring the light produced by a scintillation compound as a result of the generation of .sup.14 CO.sub.2 by the action of the bacteria on various .sup.14 C-labeled carbohydrates, amino acids, alcohols, acid salts, etc.
While the invention might most commonly be utilized for the identification of medically significant bacteria, it has utility in the characterization of algae, protozoa, fungi, yeasts and viruses, and even may find potential application in the characterization of active enzymes.
The ability to identify a biologically active agent is of obvious importance, in medicine, in pharmaceutical testing, in the food processing industry, in research applications, and in many other fields. Prior art procedures for identifying bacteria involve long, drawn out and tedious sequences of culturing and complex observations. Results are generally not available for 24 to 48 hours or longer, and even then are fraught with uncertainty due to the subjective nature of observations which must be made by individual technicians.
Methods have been proposed for the detection of biological activity by measuring the .sup.14 CO.sub.2 produced by fermentation of .sup.14 C-labeled fermentable substances; see Waters, U.S. Pat. No. 3,676,679; Wagner, Principles of Nuclear Medicine, pp. 796-7, published by W. B. Saunders, Philadelphia, 1968. However, the thrust of such prior efforts has been toward simple detection of the presence or absence of any biologically active species in the system. Once biological activity was found, it was still necessary to resort to the old culturing and observation procedures in order to identify the biologically active agent.
It has been known for some time that not all fermentable substrates are broken down into simpler compounds by all biologically active agents. In other words, biologically active agents show a certain selectivity in the substrates which they will ferment. This gives rise to a pattern of activity or "fingerprint" which is characteristic for each species of biologically active agent and which thus may be useful in identifying particular biologically active agents.
The fingerprint or activity pattern of a given biologically active species may be related to standard classification schemes by the use of standard common known organisms.
As used herein, the term "biologically active agent" is intended to refer to various types of microorganisms and related substances including fungi, protozoa, algae, yeasts, bacteria, viruses, enzymes, etc.
It is an object of the present invention to provide a method and apparatus for characterizing biologically active agents.
More particularly, it is an object of the invention to provide a method and apparatus for identifying biologically active agents by determining a characteristic fermentation activity pattern or fingerprint for such agents.
It is a further object of the invention to provide a method and apparatus capable of providing objective data on a biologically active agent without the necessity of subjective observations by a laboratory technician.
It is an object of the invention to develop a simple, preformed assembly for characterizing a biologically active agent which requires little operator handling.
It is another object of the invention to provide a simple inexpensive apparatus which may be economically discarded after a single use.
It is yet another object of the invention to provide a method and apparatus for characterizing a biologically active agent which can be readily automated.
It is also an object of the invention to provide a method and apparatus in which incubation of the test sample and subsequent analysis thereof take place in the same chamber.
It is also an object of the invention to provide a method and apparatus for characterizing biological activity which can provide useful information much more rapidly than prior art methods.
Further objects of the invention will appear from a consideration of the following specification.